Field of the Invention
This invention relates to new pourable and free-flowing granules containing bleach activators for washing laundry in a binder phase as their principal constituent, the binder phase predominantly containing surfactants which are solid at room temperatures and moderately elevated temperatures, for example up to about 40.degree. C. The invention also relates to a process for the production of the new bleach activator granules.
Inorganic peroxy compounds which dissolve in water with release of hydrogen peroxide, such as sodium perborate and sodium peroxycarbonate, have long been used as oxidizing agents for disinfection and bleaching purposes. The oxidizing effect of these substances in dilute solutions is governed to a large extent by temperature. Thus, with perborate in alkaline bleach liquors, sufficiently rapid bleaching of soiled textiles is only achieved at temperatures above 60.degree. C. At lower temperatures, the oxidizing effect of the inorganic per compounds can be improved by addition of activators for which numerous proposals have been published in the literature. The addition of these activators can increase the bleaching effect of aqueous peroxide solutions to such an extent that they are active at temperatures of only 30.degree. to 60.degree. C., i.e. at the temperatures required for the washing of delicate fabrics.
However, these activators, for example from the class of N- and O-acyl compounds, are highly sensitive to hydrolysis, above all in the presence of the alkaline ingredients typically used in detergents. The resulting problems for the stability of the laundry detergents in storage are aggravated by the fact that the activators are often poorly soluble in water so that very fine-particle materials with rapid dispersibility should be used. However, this fineparticle form promotes greater hydrolysis of the activators in storage on account of the increased surface.